The present invention relates to a frame structure for battery powered industrial vehicles.
FIG. 6 illustrates a reinforced frame structure for a battery-powered forklift, which is disclosed in Japanese Unexamined Patent Publication No. 5-254460. A front cross plate 52 and a rear cross plate 53 are coupled to the front and rear ends of a lower frame 51, respectively. The front cross plate 52 and the rear cross plate 53 are coupled to each other by upper side bars 54 and a lower side bars 55. Each lower side bar 55 has an L-shaped cross section.
The upper side bars 54 are welded to the plates 52, 53. The lower side bars 55 are fixed to the plates 52, 53 by T-shaped joiners or by flange joiners (not shown). A battery chamber 56 is defined by the upper side bars 54, the lower side bars 55, the front cross plate 52 and the rear cross plate 53. A battery (not shown) is accommodated in the battery chamber 56.
The frame structure of FIG. 6 may be used in a forklift. When such a forklift carries an object, great stress is applied to the welded points of the frame structure. The upper side bars 54 reinforce the frame structure to resist the stress.
When changing the battery, the battery is lifted from the battery chamber 56. However, since the battery may be very heavy, lifting the battery is troublesome. Alternatively, the battery may be removed horizontally from the battery chamber 56. However, in this case, one of the upper side bars 54 must be removed.
Removing one of the upper side bars 54 causes the welded points of the other side bar 54 and the welded points of the lower side bars 55 to receive greater stress. Accordingly, the life of the frame structure is shortened.
The battery may be removed horizontally over one of the upper side bars 54, which eliminates the necessity for removing the upper side bars 54. However, the battery must be located at a relatively high position, which raises the driving position of the operator. That is, the height of the driver""s seat is raised accordingly. The head guard of the forklift must also be raised. A higher head guard of the forklift hinders indoor operation of the forklift.
Accordingly, it is an objective of the present invention to provide a reinforced frame structure for a battery powered industrial vehicle that permits a low position of a battery in the vehicle and allows the battery to be removed horizontally.
To achieve the foregoing and other objectives and in accordance with the purpose of the present invention, an improved frame structure for an industrial vehicle is provided. The frame structure includes a lower plate, a front frame portion, a rear frame portion and a battery chamber. The front frame portion is spaced apart from the rear frame portion and the battery chamber is located between the front frame portion and the rear frame portion. The battery chamber has an opening at a side of the frame structure for receiving a battery. The frame structure further includes a coupler for coupling the front frame portion with the rear frame portion. The coupler extends along the periphery of the opening.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.